Question

I put UIButton on UIVIewController by StoryBoard.

in xxxVIewController.h

@interface xxxViewController : UIViewController{

IBOutlet UIButton *But;
}
@property (retain, nonatomic) IBOutlet UIButton *But;

I would like to access “*But” from another class to change setimage of UIButton.

I think if I can get the instance of UIViewController,it is solved…..

Does anyone give me the hint

---

thanks He-Was ,Jasper Blues I added comments .

One is xxxViewController which doesn’t contain navigation controller.
it contains only four buttons.

The other is TimerClass (NSObject)
which manage the time of application.

TimerClass class has timer.
What I want to do is
changing the button color on xxxViewController every a few seconds from TimerClass.

I can access TimerClass method easily.
because xxxViewController has TimerClass instance.

But xxxViewController was made by automatic,so I am not sure how to get xxxViewController instance from TimerClass.

Answer 1

I would setup xxxVIewController as a delegate for TimerClass and when you create your TimerClass instance, set the delegate to self.

ie:

self.timer = [[TimerClass alloc] init];
self.timer.delegate = self;  // This assumes that you have already created a declared property called delegate in your `TimerClass` class

Then, when it is time to update the button, you should call a delegate function in xxxVIewController and have it update its own button:

// Or whatever method that you want called
if (self.delegate respondsToSelector(@selector(changeButtonColor)))
{
    [self.delegate changeButtonColor];
}

Read up on protocols if you aren’t familiar and you will see a good way to implement this in a more general fashion.